Infusion device

ABSTRACT

An infusion device in which a back-flow check valve is provided at an opening communicated with an air and medical fluid injection groove formed along the length of the needle body, said check valve being made of a flexible material such as rubber or soft plastics and having its forward end formed spherically or in other similar configuration, with a slit being formed at the front thereof, and whereby either air or liquid medicine, as the case may be, caused to flow in the injected direction when so desired.

1 51 May 16,1972

3,217,711 11/1965 Pecina et 128/214 C [54] INFUSION DEVICE [72]Inventor:

S N m T. A w L P P A R O m E T. A P N m 0 F Kousou Yokoyarna, Hiroshima,Japan CCCM 4442 111/ 222 ///2 0088.1 222 [7 3] Assignee: Japan MedicalSupply Co., Ltd.,

Hiroshima-K911119111 1,225,859 2/1960 France... [22] Filed: July 8, 19701,464,988 3/1966 France 1, 538,728 8/1941 Great [2]] App1.No.: 53,102

Britain....

Examiner-Dalton L. Truluck Primary Foreign Application Priority DataJuly 12, 1969 Attorney-Lawrence 1. Field.lapan...................................44/65523 2,757,670 8/1956Ogle...... ...............,...........,128/214 C 3,092,106 6/1963128/214 C lClaim, 5 Drawing Figures Butler INFUSION DEVICE The presentinvention relates to an infusion set and more particularly to aninfusion device having animproved air and liquid medicine flowingsection.

In the courseof a surgical operation, there often arises an occasionwhen it is desired to mix some other medicine in a liquid medicine orblood during infusing or transfusing of the liquid medicine or bloodfrom a vial or the like by an infusion or transfusion means. Aninfusiondevice designed to meet such necessity is proposed in corpendingJapanese Utility Model Registration Application No. 58,543/68filed on'July 1 1, 1968 by the same applicant as the present application. Theinfusion device of the just mentioned application comprises a branchedcylinder provided atthebase ofthe sheath of the needle body and incommunication with an air injection groove, a check valve providednearthe forward end of the fluid through-passage holein said branchedcylinder, and a cylindrical structure having an internal taper on itsinner wall, whereby during infusion of a fluid medicine'from a-medicinebottle, some other desired medicine may beintroduced into said medicinebottle through-said cylindrical structure and air injection groove andmixed in the main fluid medicine. This infusion device, however, hadseveral serious defects. For instance, the check valve used in the airand'liquid medicine passage is smallin size and is also of a type wherethe valve body makes mechanical motion, so that such infusion deviceruns into trouble during use and also couldnot stand long=time use.

The present invention aims at overcoming all of suchdefectsand'difficulties involved in the conventional devices, and it istherefore a primary object of the present inventionto provide a noveland'improved medical fluid-infusing instrument characterized by use of aback-flow preventing valve with a simple structure having nomechanicalmovable parts such as have been used in the previously knownconventional devices in the air and liquid medicine passage, so as topermit infusion and proper mixing, as desired, of some other additivemedicine into the vial of a principal fluid medicine through said airand liquid medicinepassage'during infusionof said principal liquidmedicine to a human body from the vial.

It is another object of the present inventionto provide a novel medicalfluid infusing instrument which can stand longtime use. i

The above and other objects contemplated by the present invention areaccomplished by providing a novel medical fluid infusion instrumentcomprising: a collecting needlebody having a central hollow for formedlongitudinally thereof for passage of liquid medicine and an air andliquid medicine injection groove formed longitudinally in the side wallthereof, a sheath having a branched cylindrical portion which isprovided at the bottom of said sheath in communication with said air andliquid medicine injectiongroove and adaptedto sheath or cover saidneedle body, and a cylindrical structure provided with a back-flowpreventing valve consisting of a hollow valve section which is formedspherically or in other similar configuration of a flexible materialsuch as rubber or resin so as to allow passage of air and liquidmedicine only in the'direction of injection and which has a slit formedat its front end, and a hollow conduit portion formed of same materialasand integrally with said valve section, said cylindrical structure having a configuration to fit with said branched cylindrical portion.

Now, the present invention will be described in more detail by way ofits preferred embodiment with reference to the accompanying drawings, inwhich:

FIGv 1 is a front view partially broken away of a medical fluid infusinginstrumentaccording to the present invention;

FIG. 2 is a partial vertical sectional view of the medical fluidinfusing instrument of FIG. 1;

FIG. 3 is an enlarged sectional view of a part of said infusinginstrument, showing the passage of air and liquid medicine;

FlG. 4a is a front view of a back-flow preventing valve used in the airand liquid medicine passage in the present fluid infusing instrument;and

FIG. 4b'is a sectional view taken along the line 4b- 4bof FIG. 4a'and inthe direction of arrows in FIG. 4a.

Referring-first to FIGS. land 2, thereis shown-amedical fluid infusinginstrument, generally designated by reference number 1, according to thepresent invention. :Reference number 2 denotes a fluid collecting needlebody which has formed in its center and longitudinally thereof a liquidmedicine inlet "5 and an innerlbore 3 forpassage of liquid medicineleading to a bottom end portion 90. At the top end of said needle 'body2 is planted a needle 7 made of ahard material suchas metal. Denotedbyreference-number ti'are thegrooves for passage of liquidmedicine whichare formed on both sides of the needle body so as toextend from thetopend of saidneedle body to the liquid'medicine inlet -5. lnthe externalwall of said-needle body 2 is forrnedaa'longitudinally extending. airand liquid'medicine injection. groove 4 which is reduced in width andsoiarranged that one end ispositioned closer to the top end of theneedlebodylthan to theliquid medicine inlet "5. Reference number "10indicates a sheath covering the entire outerperiphery of the needlebody2 except for the opening of the liquidmedicine inlet 5, whereby saidair and liquid medicine injection groove 4 is also covered, with onlythe end thereof beingleft exposed. Said sheath '10 is tapered toward itsforward end so that the diameter of said forward end will besubstantially .equal tothat of the'needle body. At the base 12 of saidsheath is provided a circular socket 13-which is adapted to'receivea'protuberance8 onthe base'9 of the needle body tothereby securethesheath tothe needle body. Right above the base of said sheath I0is,provided a protruding branched cylindrical portion 11 arranged toconnect to a cylindrical structure 14 which has formed therein an airand liquid medicine a bore 17 communicated 'with the air and liquidmedicine injection groove 4. As will be seen-in the drawing (see FIG.2), the inner wall 16 of the cylindrical structure 14 isgiven a taper soas to fit with a syringe or the like.

ln the center of the inner end of said cylindrical structure 14 isprovided a back-flow preventive valve 25 (see FIGS. 4a and 4b) which,asbest shown inFIG. 3, consists of a'hollow valve section 26 formedspherically orin other similar configuration with a flexible materialsuch as rubber or plastic, with a slit 26a'being formed at itsfront'end, and a hollow conduit portion '27 made of the samematerial asand integrally with said valve section 26. The back-flow preventivevalve'25 has an extremely simplestructureas shown and is so constructedthat theslit 26a is opened only when the pressure applied to its innersurface is higher than the pressure applied to its outer surface so asto allowpassage of air or liquid medicine in the direction of arrow.Normally, the slit 26a is kept closed to inhibit movement of fluid.Reference number 28 designates a liquiddropping cylinder mounted betweenthe bases9 and 12, and 29a cylindrical element in which a suitablefilter means 30 is installed and which is arranged to fit into thecylindrical structure 14.

ln use of the present invention, the pointed end of the needle body 2 isthrust into a rubber plug of a vial or the like in element 29 isprovided in the flow passage hole 17 in the cylindrical structure 14,any dust, germs or other undesirable substances mixed in the air areeliminated. Thus, when the pressure exerted by the cleaned air againstthe inner wall of the back-flow preventing valve 25 exceeds the pressureagainst its outer wall, the slit 26a is opened to produce an air streamrunning in the direction indicated by arrow in the drawing. When thepressures given to the inner and outer walls of 'the back-flowpreventive valve 25 are equal to each other, 'or

when the pressure against the outer wall is larger than that against theinner wall, said slit 26a is kept closed to inhibit movement of air, sothat there is no outflow (back-flow) of air in said vial to the outsideof the fluid infusion instrument.

in the course of infusion of a liquid medicine, when it is desired tomix therein some other desired liquid medicine, the filter-attachedcylindrical member 29 located in the passage 17 in the cylindricalstructure 14 is removed, and instead, a suitable syringe or the like isfitted thereinto whereby to mix a desired medicine into the vial throughthe same route as the above-said air passage. The internal taper formedon the inner wall of the cylindrical structure 14 facilitates fitting ofthe syringe or the like thereinto. When other medicine is being mixedinto the vial, air injection into said vial is interrupted, but sincethe positive pressure therein is not excessively reduced by introductionof such other medicine into the vial, there is no need of halting theliquid infusing operation. In this case, the back-flow preventing valve25 operates in just the same manner as in the case of air injection, sothat any back-flow of liquid medicine from the via] to the outsidethereof through the air and liquid medicine injection groove 14 isperfectly inhibited.

Thus, according to the fluid infusing instrument of the presentinvention, it is possible to mix in the liquid medicine, which is beinginfused, other desired fluid medicine, whenever so desired, quickly andwith extreme ease. Particularly, in the present invention, a backflowpreventing valve 25 having an extremely simple construction with nomechanical movable parts such as used in the conventional devices isemployed in the air and liquid medicine flowing passage in theinstrument, so that any possibility of causing serious troubles due tofailure of check valve during fluid infusing operation is obviated toensure safety in operation, and also the instrument can stand long use.

What i claim is:

l. A fluid infusing instrument comprising:

a fluid collecting needle body having a sharpened end and having formedtherein a longitudinally extending central bore along the length of saidneedle body for passage therethrough of liquid medicine, said needlebody also having a longitudinally extending air and liquid medicineinjection groove formed in the external side wall of said needle bodyand along the length thereof, both said bore and said injection grooveextending parallel to each other, said needle body including a sideopening communicating with said bore and located below said sharpenedend;

a sheath concentrically mounted on said needle body, extending from apoint below said side opening and substantially the remaining length ofthe needle body, said sheath including a branched cylindrical portionwhich is located adjacent the bottom of said sheath and whichcommunicates with said air and liquid medicine injection groove;

a hollow valve section consisting of said sheath and a cylindricalstructure in said branched cylindrical portion and a back-flowpreventive valve formed spherically of a flexible material with a slitbeing formed at the front end thereof, and a hollow conduit portion madeof the same material as and integrally with said valve section anddisposed to permit passage of air and liquid medicine only in thedirection of injection, said valve being confined within said branchedcylindrical portion, whereby air or other desired liquid medicine can bepassed, as desired, in the injected direction through said air andliquid medicine injection groove, said back-flow preventive valve andsaid cylindrical structure.

k I i i

1. A fluid infusing instrument comprising: a fluid collecting needlebody having a sharpened end and having formed therein a longitudinallyextending central bore along the length of Said needle body for passagetherethrough of liquid medicine, said needle body also having alongitudinally extending air and liquid medicine injection groove formedin the external side wall of said needle body and along the lengththereof, both said bore and said injection groove extending parallel toeach other, said needle body including a side opening communicating withsaid bore and located below said sharpened end; a sheath concentricallymounted on said needle body, extending from a point below said sideopening and substantially the remaining length of the needle body, saidsheath including a branched cylindrical portion which is locatedadjacent the bottom of said sheath and which communicates with said airand liquid medicine injection groove; a hollow valve section consistingof said sheath and a cylindrical structure in said branched cylindricalportion and a back-flow preventive valve formed spherically of aflexible material with a slit being formed at the front end thereof, anda hollow conduit portion made of the same material as and integrallywith said valve section and disposed to permit passage of air and liquidmedicine only in the direction of injection, said valve being confinedwithin said branched cylindrical portion, whereby air or other desiredliquid medicine can be passed, as desired, in the injected directionthrough said air and liquid medicine injection groove, said back-flowpreventive valve and said cylindrical structure.